The invention pertains to a method for preparing fold lines in laminated materials based on cardboard for the production of containers.
The invention also pertains to an apparatus for preparing fold lines in laminated materials based on cardboard for the production of containers.
The invention also pertains to fiber composites with thermally activatable solvents in conjunction with a vapor barrier to prevent the escape of the solvent.
In the production of packages of cardboard, blanks are produced out web material during the course of a first production step, and then the blanks are usually provided with folds so that the cardboard composite can be folded to form the container to be produced. When a cardboard composite of the laminated type is folded, both elastic and plastic stresses develop in the area of the fold. The plastic stresses can lead to displacements of the material in the area of the fold joint. The material displacements generate shear stresses between the individual fiber layers of the cardboard up to a material-dependent limit value.
When the limit, i.e., the so-called “shear fracture stress” value, is exceeded, the layers of material delaminate.